Clubface of a golf club and method for fabricating the same

ABSTRACT

A manufacturing method of a clubface of a golf club reduces the amount of the metallic material used and enhances production. The manufacturing method includes the following steps: a metal powder and a binder are mixed to form a mixture; the mixture is shaped by a clubface mold to form a primary clubface; the primary clubface is then heated to a sintering temperature of the metal powder to form a clubface, before the clubface is finally compacted to make it stronger and increase the clubface&#39;s density.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to a clubface of a golf cluband a method for fabricating the same, which is a clubface a golf clubhaving an integral structure and using the technologies of powdermetallurgy and injection molding.

2. Description of the Prior Art

Because the clubface of a golf club must withstand massive impactforces, it needs to be constructed of high intensity metallic materials.Another aspect of the prior art is that clubfaces of golf clubs usuallyhave a curved surface rather than planar one. Therefore, themanufacturing processes are very complex. The higher intensity the metalhas, the higher its melting point is. Therefore conventional castingmethods cannot make clubfaces.

Reference is made to FIG. 1, which is a side view of a clubface of agolf club according to prior art. A clubface 94 is fixed on a club head92 of a golf club 9. A conventional method uses a very hard tool that isassembled on a lathe or a milling machine to cut out the curved surface.However the conventional method wastes a processed portion 96 as shownin FIG. 1, which is an expensive metal. Moreover, the producing methodcannot be speed up to reach the needs of mass production.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide a clubface of a golfclub and a method for fabricating the same, which raises output to reachmass production scale, and also reduces waste.

In order to achieve the above objectives, the present invention providesa manufacturing method for a clubface of a golf club, which comprisesthe following steps: a metal powder and a binder are mixed to form amixture; the mixture is shaped by a clubface mold to form a primaryclubface; the primary clubface is then heated to a sintering temperatureof the metal powder to form a clubface, and compacting the clubfacefinally to make it stronger and increase the density of the clubface.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and objectives other than thoseset forth above will become apparent when consideration is given to thefollowing detailed description thereof. Such description makes referenceto the attached drawings, wherein:

FIG. 1 is a side view of a clubface a golf club according to prior art;

FIG. 2 is a flowchart of a manufacturing method of a clubface of a golfclub according to the present invention; and

FIG. 3 is a side view of a clubface a golf club according to the presentinvention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Reference is made to FIG. 2, which is a flowchart of a manufacturingmethod for a clubface of a golf club according to the present invention.The manufacturing method of a clubface chiefly uses powder metallurgy(P/M) technology, which includes at least four steps: a mixing step 10,a shaping step 20, a heating step 30 and a compacting step 40.

In the mixing step 10, a metal powder and a binder are mixed to form amixture. The metal powder preferably has the characteristics of highhardness and low specific weight. For example, Ti (titanium) or atitanium alloy that has the characteristic of high hardness so that itcan withstand strong impacts. Titanium is a gray metal, of which thespecific weight is 4.5 and the melting point is 1668 degrees centigrade.It is a very special metal, is very light and very firm and is able toendure erosion. Tungsten carbide alloy also has high hardness, but thespecific weight is higher. It is better that the metal powder issmaller, which is usually under 80 μm. However this does not limit thediameter of the metal powder. The smaller the metal powder is the biggerthe surface area is, and the space thereof is reduced. Thereby, themetal powder is stacked more closely, and is sintered together moreeasily to reduce the required time of the heating step 30. The size ofthe metal powder affects not only the density of the sintered product,but also the performance thereof. The smaller the metal powder is thelarger the specific surface area (area/weight) is. A large specificsurface area is very important. The binder is used for combining themetal powder, and can be a macromolecule binder or an organic binder(such as thermoplastic resin or wax).

In the mixing step 10, which can further include a step of providing astirring machine for mixing and compressing the mixture, the mixture isformed using the metal powder and the binder. The mixture is then usedas a raw material for shaping.

In the shaping step 20, the present invention chiefly uses injectionmolding technology (metal injection molding (MIM)) to mold the mixtureand form a primary clubface via a clubface mold. During the process ofinjection molding, an injection-molding machine is required. Firstly,injection molding machine needs a preheating step during the process ofinjection molding, which heats the mixture so that it takes on some ofthe characteristics of a fluid. Next, the fluid mixture is injected intothe clubface mold. At this stage the mixture is still in a soft state asit is yet to go through the heating stage that properly forms, hardensand strengthens the clubface. Injection molding technology is a proventechnology, which can increase production speed.

The present invention is not limited by to injection molding technology,and also can use press-molding technology. Firstly, a controlled amountof the mixture powder is fed into a precise mold (die) and the mixtureis compacted in the mold by an upper and lower compacting machine togain a primary clubface. The primary clubface is a compacted component,which is usually said to be in a “green” or soft state.

In the heating step 30, the primary clubface is heated to a sinteringtemperature of the metal powder to form a clubface. After pressing, theprimary clubface is sintered by heating, and the binder therein willbecome dehydrated. In the heating step 30, the primary clubface isusually passed through an ore-sintering furnace in which bothtemperature and atmosphere are strictly controlled by computer. Theprimary clubface is heated, so that the metal powders (particles) arefused, or sintered, together into a solid mass (the clubface). Duringthe sintering step, a protective air, such as an inert gas likenitrogen, is aerated into the ore-sintering furnace to avoid the metalpowder becoming oxidized. The sintering temperature is just below themelting point of the principal material, and is usually two thirds ofthe melting point of the principal material (i.e. the metal powder),which will allow the sintering process to take place. Of course thesintering temperature can reach or exceed the melting point. Forexample, the melting point of titanium is 1668 degrees centigrade, andthe sintering point is over 1125 degrees centigrade.

The final step is enhancing structural intensity, which includes acompacting step of compacting the clubface. Therefore, the clubface willbe more compact and solid than the sintered mass. The primary clubfaceusually is slightly bigger that the predetermined size of the clubface,so that it will reach the predetermined size after compacting.

The above-mentioned steps complete a clubface of a golf club accordingto the present invention. The present invention chiefly applies thetechnolygies of powder metallurgy and metal injection molding (MIM). Theshape of the clubface according to the method of the present inventioncan be changed easily. Reference is made to FIG. 3, which is a side viewof a clubface of a golf club according to the present invention. Theclubface 1 has a main portion 12 and a curved striking-surface 122formed on a top surface of the main portion. The main portion 12 is madeof a single metallic material with a sintered structure. Via themanufacturing method of the present invention, the striking-surface 122can be easily made with various shapes to enhance the ball-controllingability, such as that formed with a plurality of protrusions 124 toincrease the ball-grasping ability, or with a plurality of grooves.

A summary of the characteristics and advantages of the present inventionare as follows:

1. The clubface of a golf club according to the present invention can tobe easily made with various shapes to enhance the ball-controllingability.

2. The manufacturing method of the clubface of a golf club according tothe present invention can reach the scale of mass production.

3. The clubface of a golf club according to the present invention doesnot waste material, and needs even fewer material than the prior artbecause of the sintered structure, so that can reduce the costs of themetallic material.

Although the present invention has been described with reference to thepreferred embodiments thereof, it will be understood that the inventionis not limited to the details thereof. Various substitutions andmodifications have been suggested in the foregoing description, andothers will occur to those of ordinary skill in the art. Therefore, allsuch substitutions and modifications are intended to be embraced withinthe scope of the invention as defined in the appended claims.

1. A manufacturing method of a clubface of a golf club, comprising:mixing a metal powder and a binder to form a mixture; shaping saidmixture via a clubface mold to form a primary clubface; heating saidprimary clubface to a sintering temperature of said metal powder to forma clubface; and compacting said clubface.
 2. The manufacturing method ofa clubface of a golf club as in claim 1, wherein said metal powder istitanium or a titanium alloy.
 3. The manufacturing method of a clubfaceof a golf club as in claim 1, wherein said binder is a macromoleculebinder or an organic binder.
 4. The manufacturing method of a clubfaceof a golf club as in claim 1, wherein said mixing step comprises a stepof providing a stirring machine for mixing and compressing said mixture.5. The manufacturing method of a clubface of a golf club as in claim 1,wherein said shaping step comprises a step of preheating said mixture toa point where the mixture takes on the characteristics of a fluid. 6.The manufacturing method of a clubface of a golf club as in claim 5,further comprising a step of providing an injection molding machine toinject said mixture into said clubface mold.
 7. The manufacturing methodof a clubface of a golf club as in claim 1, further comprising a step ofdehydrating said binder in said primary clubface during the step ofheating said primary clubface.
 8. The manufacturing method of a clubfaceof a golf club as in claim 1, wherein said heating step furthercomprises a step of providing an ore-sintering furnace to sinter saidprimary clubface during the step of heating said primary clubface. 9.The manufacturing method of a clubface of a golf club as in claim 8,further comprising a step of aerating a protective air into saidore-sintering furnace.
 10. The manufacturing method of a clubface of agolf club as in claim 1, wherein a range of said sintering temperatureis two thirds of a melting point of said metal powder up to said meltingpoint of said metal powder.
 11. A clubface a golf club producedaccording to the method of claim 1, formed by injection molded metalpowder, comprising: a main portion; and a curved striking-surface,formed on a top surface of said main portion.
 12. The clubface of a golfclub as in claim 11, wherein said curved striking-surface is formed witha plurality of protrusions.